We can perform a wide variety of traditional power system analyses, such as an assessment of the impact of EVs or PV on distribution feeder voltage profiles.  However, there are a few things we can do that many other similar firms can't.

• We specialize in modeling the dynamic and transient response of systems including distributed power electronics, complex voltage regulation controls, and other specialized or unusual situations.  We can handle microcontroller-based control methods that aren't always well modeled by traditional linear representations.  We work closely with power electronics manufacturers and utilities to make sure we get the models right, and we verify all of our models as extensively as available data allow.
• We have considerable experience working with cosimulation of power systems and associated communications systems.  We can simulate the command-and-control aspects of a power system using communications models of whatever protocol is applicable, and to whatever level of detail is required by the application.

NPPT performs a variety of services for utility clients.  We collaborate with utilities to ensure that new technologies (especially photovoltaics and electric vehicles) can be deployed safely, cost-effectively, and with a minimum of headaches.  We start by listening, because the utility's own engineers know the system best; we then work with those engineers to understand the situation, identify issues, and develop and deploy solutions that work.  When necessary, we also collaborate with equipment manufacturers to make new solutions feasible.  A few examples:

• Investigations of systems with multiple distributed generators.  Increasing numbers of cases are beginning to arise in which utilities are concerned about potential adverse interactions between multiple distributed generators on a feeder--for example, how the presence of one distributed generator might impact the islanding detection capabilities of another.  NPPT has the expertise and collaborative connections needed to determine whether a problem exists, and if one is found, to work with inverter manufacturers or other parties to develop and deploy a remedy.
• Islanding investigations.  We work with utilities who are interested in islanding prevention, and also in intentional islanding of distributed energy resources.  Most projects in this category involve system studies to ensure that islanding is not an issue, often in unusual circumstances like the ones described above.  Other projects involve seamless transitions to an intentionally-islanded case, or the dynamics of an intentionally islanded system (also known as a "microgrid" or a "low-inertia power system").  We also have experience with the development of generator/storage controls for intentionally islanded systems.
• Impact studies.  We perform studies to determine the possible problems and benefits of distributed energy resource installations from such effects as harmonics, voltage rise, component loading, and interaction with protection schemes.
• Distribution system readiness for electric vehicles.  It appears that EVs' time may finally be coming, but rapid chargers and even overnight chargers can put new strains on old equipment.  We perform studies to identify problems and develop solutions.
• Compliance studies.  NPPT works with utilities to ensure that proposed distributed generation installations meet the utility's and the government's standards.
• Feasibility studies.  We work with clients to determine payback times of distributed energy projects.

NPPT has a long history of collaboration with the manufacturers of the power electronics used to interface distributed generation equipment and plug-in electric vehicles to power systems.  We focus on cost-effective, market-sensitive solutions that address the needs of both the manufacturer and the manufacturer's customers.  Some examples:

• Controls development.  We work with manufacturers to develop converter controls that solve a wide variety of complex system-level problems.  Some of these are market-wide solutions, such as innovative islanding prevention methods or ways to make electric vehicle fast chargers more grid-friendly.  Some are application-specific, such as those that arise from a study of an interaction between multiple distributed energy resources in a particular installation.  Some have immediate application, while others are more forward-looking.
• Transient studies.  We can assist manufacturers in determining how their converters will respond in a variety of transient situations, usually where the transient is induced by an event on the system to which the inverter is connected.  We can examine transient impacts on both hardware and software.
• Power electronics design.  We work on the design of power electronics, especially those used in electric vehicles for propulsion or charging.  We can do custom designs in-house, or we can work with your designers to assist in reaching an optimal and competitive design.

NPPT's founder and principal engineer holds a PhD in Electrical Engineering from Georgia Tech in Atlanta and is a licensed Professional Electrical Engineer in South Dakota.  NPPT has over fifteen years' experience in the development of innovative solutions to difficult issues surrounding the integration of distributed resources (especially photovoltaics) into power networks, and in the development of new technologies to continually improve the integration of distributed resources into power systems without adverse cost impacts, or even while improving the economics. 

Typically, we use powerful computer modeling tools such as MATLAB/Simulink, EMTP-RV or PSCAD, or PSS/E to create an appropriate virtual laboratory that allows us to quickly test a wide variety of options with high confidence in the realism of the results.  We understand not only the software, but also the hardware we are simulating, and that enables us to create models that capture well the behaviors that need to be simulated, without cluttering the models with unneeded detail.  Throughout the process, we work closely with you to make sure we keep your needs in the forefront. 

We also have extensive experience in proposal writing and results dissemination.  If your project is still at the proposal stage, now may be a good time to contact us.

Any way you slice it, a technology that turns light directly into electricity is just pretty darn cool.  NPPT personnel have been involved in almost every aspect of photovoltaic (PV) technology.  Our experience includes:

• grid integration of PV into large-scale and small-scale (microgrid) systems
• modeling, design, specification, procurement, construction, and monitoring of grid-tied and stand-alone PV systems
  
• modeling, design, analysis, construction, and bench and field testing of PV power electronics, both module-integrated and off-module
  
• modeling, design, analysis, fabrication, and characterization of silicon PV solar cells
• development and technical support for development of codes and standards

NPPT believes that moving toward a more electrified transportation sector is strategically and economically critical for our nation and world.  We simply cannot move to a more sustainable world economy without significantly electrifying the transportation sector, through electric vehicles (EVs) and electric rail.  We are committed to using our resources and capabilities to help that to happen.

As noted above,  NPPT works in several areas of the electric transportation field.

• Power system impact studies.  Using our in-house computer modeling tools, we can conduct a wide variety of studies of the impacts of EVs on electric power networks, including studies involving the transient and dynamic performance of the EV's power electronics. We do these studies both for utilities and for power electronics manufacturers.
  
• Powertrain modeling.  We can model EV electrical systems in their entirety to assist in controls and hardware design.
• Power electronics design.  We have solid experience in the design of custom power electronics for a variety of EV applications.